JPS6090368A - Developer carrying device - Google Patents

Abstract

PURPOSE:To cause no operation failure of a guide roller by constituting so that a ring member formed on the outside circumferential surface of the guide roller which contacts by pressing to both end parts of a photosensitive body is provided with a projecting part on both end parts of its inside circumferential surface. CONSTITUTION:Guide rollers 9, 9' whose diameter is larger than a non-magnetic sleeve 3 are provided on both ends of a permanent magnet roll 2 rotating opposingly to a photosensitive body 1, and its outside circumferential surface contacts by pressing to both end parts of the photosensitive body 1 and rotates, and maintains a developing gap (g) so as to be constant. As for the roller 9, a ring member 11 is fit-installed to the outside circumferential surface of a bearing 10, and a projecting part 12 is provided on both end parts of the inside circumferential surface of the ring member 11, therefore, it does not fall out of the bearing 10. Accordingly, the developing gap (g) between the photosensitive body 1 and the sleeve 3 is always kept constant, and the ring member 11 does not fall out, therefore, the guide roller 9 causes no operation failure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developer conveying device, and in particular to a developing device and a magnetic cleaning device for visualizing an electrostatic latent image formed on the surface of an image carrier using a magnetic developer. 111'8j to the developer conveying device used for etc.

In image forming apparatuses such as electronic photocopiers and facsimile printers, a rotating drum (hereinafter referred to as a photosensitive drum) that holds a photosensitive layer on its surface is used as a device for developing an electrostatic latent image formed on the surface of a photosensitive member. It is known that a permanent magnet roll is arranged around a body drum (called a body drum).

This permanent magnet roll has a non-magnetic cylindrical sleeve (hereinafter referred to as non-magnetic sleeve) and a permanent 4fl r:i member having a plurality of It poles on its inner surface, and the non-magnetic sleeve and the permanent magnet The relative rotation of the members transports the magnetic developer held on the non-magnetic sleeve to bring it close to or in contact with the electrostatic latent image. Examples of this magnetic developer include magnetic powder such as iron powder and fly powder;
Two-component developers, which are mixed powders of 1-hener and 1-hener, and one-component, Ml-based 1-ners, whose main components are resin and magnetic powder, are commonly used.

In the above developing device, a3'C is the gap between the photoreceptor surface and the permanent magnet roll surface (hereinafter referred to as the "developing 1" top).
Although it is important to always maintain the development gap constant in order to prevent uneven development, it is virtually impossible to maintain the development gap constant due to eccentricity of the photoreceptor drum. In particular, when using magnetic toner as a magnetic developer, the thickness of the toner layer on the non-magnetic sleeve is small (usually 1.0 to 0.1
(m1ll), the development gap also becomes narrower. Therefore, if the C1 development gap fluctuates and becomes too narrow, for example, toner agglomeration or crushing will occur.

Therefore, in order to eliminate such problems, for example, as described in Japanese Patent Application Laid-open Nos. 54-25839 and 55-129367, both ends of the permanent magnet roll are connected to both ends of the photoreceptor drum. It has been proposed that the guide roller be rotatably mounted. Therefore, since this type of conventional guide roller is formed by fitting a resin ring member into a bearing, it is particularly difficult to use when the ring member has a thin wall thickness (approximately 0.5 to 2 mm). However, there was a problem in that the ring member came out while the guide roller was rotating.

SUMMARY OF THE INVENTION An object of the present invention is to provide a developer conveying device that eliminates such drawbacks and eliminates the malfunction of the guide roller.

The structure of the present invention is such that a conveyor roll that holds developer is rotatably arranged opposite to an image carrier drum, and guide rollers that come into contact with both ends of the image carrier drum are provided at both ends of the conveyor roll. @A3 in the developer conveyance device 1lli which is a rotatable device. A protrusion is provided on the developer transport device.

Embodiments of the present invention will be described below based on the drawings.

Here, FIG. 1 is a cross-sectional view of a developing device using a developer conveying device according to an embodiment, and FIG. 2 is a cross-sectional view of the developer conveying device in FIG. 1, and FIG. is a sectional view of the guide roller, and FIG. 4 is an enlarged view of the main part of FIG. 3.

In the figure, 1 is a photosensitive drum, 2 is a permanent magnet roll,
3 is a non-magnetic sleeve, 4 is a permanent magnet member, 5 is a permanent magnet, 6 is a shaft, 7.7' is a flange, 8°8' is a bearing, 2
8, 8' constitute a conveyance roll. 9.9' is a guide roller, 10.degree. 10' is a bearing, 11.11' is a ring member, 12 is a protrusion, and 2 to 12 constitute a developer conveying device. 13 is a toner tank, 14 is a doctor member, 1
5 is a magnetic toner.

In FIGS. 1 and 2, a permanent magnet roll 2 is placed opposite a photoreceptor drum 1 having a photoreceptor layer (not shown). The permanent magnet roll 2 has a non-magnetic sleeve 3
A permanent magnet 5 having a plurality of magnetic poles on its surface inside the magnet.
It has a permanent magnet member 44 fixed to the shaft 6,
The shaft 6 is rotatably supported by a flange 7° 7' through bearings 8, 8' at both ends thereof. Further, on both sides of the flange 7 and 7', large-diameter guides 9 and 9' are rotatably provided on the flange 7 and the shaft 6, respectively. The outer peripheral surface of the guide roller 9,9' is in contact with both ends of the photoreceptor drum 1.In order to keep the developing gap O constant, the permanent magnet roll 2 or the entire developing device is equipped with a spring or the like. The guide roller 9 is forced toward the photosensitive drum 1 by a means (not shown) shown in FIG.
As shown in FIG. 4, a ring member 1 is attached to the outer peripheral surface of the bearing 10.
1 is fitted, and protrusions 12 are provided at both ends of the inner peripheral surface of the ring member 11. Note that the configuration of the guide roller 9' is also similar to that of the guide roller 9.

A doctor member 14 for regulating the thickness of the toner layer on the non-magnetic sleeve 3 is attached to the tank 13 containing the magnetic I-node 15.

In the developing device configured as described above, the permanent magnet member 4 and the non-189 sleeve 3 are rotated 2! look.

For example, when the flange 7 is fixed and the shaft 6 is prevented from rotating, the magnetic toner 15 attracted onto the non-magnetic sleeve 3 is conveyed through the doctor gap d of the doctor member 14 in the direction of the arrow in the figure. Then, the magnetic toner
When it reaches , it contacts the photoreceptor drum 1 and forms an electrostatic m-image (1!
V) and development is performed. Here, the guide rollers 9, 9' rotate following the photoreceptor drum 1, and the developing voltage V is kept constant. Note that the pressing force of the guide rollers 9, 9' against the photosensitive drum 1 must be approximately 5 to 6 kg in order to ensure an accurate development gap.
High pressure is generated at the contact area.

Further, a force in the thrust direction is applied to the guide rollers 9, 9' due to their rotation, but as described above, since the protrusion 12 is provided on the inner surface of the ring member 11.11', the ring member 11.11'' can be completely prevented from coming off from the bearing 10.10'. In this case, the radius R of the protrusion 12 is the same as the radius of the bearing 10.10', or
)J, even if it is somewhat large, it can effectively prevent the loss of 1. However, if the radius R is too large, the ring member 11
．． When molding 11', it becomes difficult to remove it from the mold, so it is preferable to make it 1/2 or less of the wall thickness.

The specific value of R varies depending on the dimensions of the bearings 10, 10' and the dimensions of the ring member 11, 11', but the outer diameter of the bearing is 15 to 20111 mφ and the wall thickness of the ring member is 1 to 2 mm. In the case of 0.2-・0.5111II1
The position is appropriate.

As explained above, the developing device using the developer conveying device according to the present embodiment has the permanent magnet roll 2, which has the permanent magnet member 4 provided inside the non-magnetic sleeve 3, attached to the photoreceptor drum 1. Guide rollers 9.9' that are rotatably arranged to face each other and abut against both ends of the photosensitive drum 1.
are rotatably attached to both ends of the permanent magnet roll 2, so that the developing gap between the photosensitive drum 1 and the non-magnetic sleeve 3 is kept constant. Guide [J
- The configuration of the rings 9, 9' is formed by fitting ring parts IJ11, 11' onto the outer circumferential surface of the bearings 10, 10', and protruding parts are formed at both ends of the inner circumferential surface of the ring members 11, 11'. 12 prevents the ring members 11, 11' from coming out during the rotation of the guide eyes 9, 9'.

Note that although the developing device was explained in the above embodiment,
The present invention is not limited to this, and the present invention is not limited to this.
274), cleaning fur brush rolls (for example, JP-A-54-116237, JP-A-I
V? 55-70865) and fur brush rolls for development (for example, a fur brush fixed to the surface of a magnetic roll as described in Japanese Patent Publication No. 54-2105 may also be used). Of course it can be applied.

As described above, overall, the present invention prevents the ring member from coming out during the rotation of the guide roller.
This invention eliminates the malfunction of the guide roller and allows for a lζ developer conveying device, and can be said to be an invention with excellent practical effects.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a developing device using a developer conveying device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the developer conveying device in FIG. 1, and FIG. The sectional view of the guide roller, FIG. 4, is an enlarged view of the main part of FIG. 3. 1... Photosensitive drum, 2... Permanent magnet roll, 3...
...Nonmagnetic sleeve, 4...Permanent magnet member, 9.9'
... Guide roller, 10.10' ... Bearing, 11
．． 11'...Ring member, 12...Protrusion part. Patent applicant Hitachi Metals Co., Ltd. Agent

Claims (2)

[Claims] (1) A transport roll that holds the developer is rotatably arranged facing the image carrier drum, and the guide rollers that come into contact with both ends of the carrier drum are rotated at both ends of the transport roll. In the developer conveying device freely attached, the guide roller is formed by fitting a ring member onto the outer peripheral surface of a bearing, and protrusions are provided at both ends of the inner peripheral surface of the ring member. A developer conveying device characterized by: (2) The developer conveying device according to claim tA13B, wherein the ring member is made of synthetic resin.